I have an iPhone which generates .HEIC file, after searching extensively the only software I found that can view .HEIC files is XnView.
If you could implement these suggestions, it'd be awesome.
Thanks!
PS: some are bugs

- Option to start XnView with "Show files in subfolders" already enabled.
- Opening a .heic file from File Explorer with XnView just opens XnView in browser mode, not in view mode.
- Add a close button to toolbar in Viewer (not currently available in the toolbar editor).
- Option to sort by file creation date, and clarify the current "Date" option is just the date modified.
- Allow backspace to close the viewer.
- Make clicking the "Zoom 100%" button a 2nd time perform a fit image to window.
- Add ability to add new toolbar buttons (currently can only modify/delete existing buttons).
- Show folder names (with View As Thumbnails only folders are unidentifiable).
- Convert the program to x64 for faster performance (maybe would help speed up high-quality zooms, which are very slow).